(Wlafiet of |kmerj> anb 



monumental ruins in the Seven Hills tell of their 

 intense association with man. 



Both the northern and the southern hemi- 

 spheres have had their heavy, slow-going floods 

 of ice that appear to have swept from the polar 

 world far toward the equator. During the great 

 glacial period, which may have lasted for ages, 

 a mountainous flood of ice overspread America 

 from the north and extended far down the Mis- 

 sissippi Valley. This ice may have been a mile 

 or more in depth. It utterly changed the topo- 

 graphy and made a new earth. Lakes were filled 

 and new ones made. New landscapes were 

 formed : mountains were rubbed down to plains, 

 morainal hills were built upon plains, and 

 streams were moved bodily. 



It is probable that during the last ice age 

 the location and course of both the Ohio and 

 the Missouri Rivers were changed. Originally the 

 Missouri flowed east and north, probably emp- 

 tying into a lake that had possession of the 

 Lake Superior territory. The Ice King delib- 

 erately shoved this river hundreds of miles to- 

 ward the south. The Ohio probably had a sim- 



249 



